Method and apparatus for rolling flat material in rolling mills or the like

ABSTRACT

A METHOD AND APPARATUS WHEREBY ONE OF THE WORK ROLLS IN A CONVENTIONAL ROLLING MILL IS HORIZONTALLY DISPLACED WITH RESPECT TO THE COOPERATING WORK ROLL SO THAT AS THE MATERIAL TO BE ROLLED APPROACHES THE BITE OF THE ROLL, IT CONTACTS AND IS WRAPPED SLIGHTLY OVER ONE OF THE ROLLS THUS DAMPENING THE MATERIAL TO ELIMINATE FLUTTERING AND GUTTERING AND PRESENTING A FLAT SURFACE FOR REDUCTION IN THE ROLL BITE.

United States Patent 1 lnventor Erasmus A. Randich Pittsburgh, Pa. [21] Appl. No. 716,478 [22] Filed Mar. 27, 1968 [45] Patented June 28, 1971 [73] Assignee Allegheny Ludlum Steel Corporation Breckenridge, Pa.

[54] METHOD AND APPARATUS FOR ROLLING FLAT MATERIAL IN ROLLING MILLS OR THE LIKE 1 Claim, 1 Drawing Fig.

[52] 0.8. CI 72/16, 72/199, 72/205, 29/17 [51] Int. Cl B2lb 17/02 [50] Field of Search 72/16, 199, 240, 205, 366, 245, 365, 205; 29/17, 18

[56] References Cited UNITED STATES PATENTS 2,095,733 10/1937 Coryell 72/205X Primary Examiner-Milton S. Mehr Attorneys-Richard A. Speer, Vincent G. Gioia and Howard R. Berkenstock, Jr.

ABSTRACT: A method and apparatus whereby one of the work rolls in a conventional rolling mill is horizontally displaced with respect to the cooperating work roll so that as the material to be rolled approaches the bite of the roll, it contacts and is wrapped slightly over one of the rolls thus dampening the material to eliminate fluttering and guttering and presenting a flat surface for reduction in the roll bite.

STRIP DIRECTION A] CONTROL MEANS PATENTEUJUN28I971 33587266 STRIP DIRECTION CONTROL MEANS METHOD AND APPARATUS FOR ROLLING FLAT MATERIAL IN ROLLING MILLS OR THE LIKE I BACKGROUND OF THE INVENTION This invention relates to a method and apparatus for rolling flat material in rolling mills and the like, and more particularly relates to a method and apparatus for offsetting one work roll with relation to the other in order to better control material thickness at high rolling speeds.

The problem of rolling flat materials in rolling mills and the like has plagued mill operators for many years and while the problem exists in both the hot and the cold mills, it is. more pronounced in the cold mill and particularly in the rolling of thin gauge materials. Further theproblem appears to beaggravated as the work roll diameter to strip thickness ratio decreases. The problem specifically lies inthe fact that when strip'is being reduced by small work rolls at high speeds, the stripentering the rolls flutters and gutters and has a tendency to gather ahead of the roll bite. in many instances such gathering results in pinching in the mill rolls causing overrolling in one area and subsequent strip breakage.

' A number of means have been oifered as a solution to'this problem; however, generally these involve intricate operations including special work rolls, power supplies, and the like.

Accordingly, it is an object of this invention to provide a simple! method and apparatus for rolling flat material in a rolling mill.

it is a further object of this invention to provide a simple method and apparatus to automatically offset one work roll in relation to the other so that the thickness and ultimate flatness of thin gauge strip can be closely and continuously controlled at high mill operating speeds.

SUMMARY OF THE INVENTION In accordance with the invention, means are provided whereby a work roll of a conventional rolling mill may .be horizontally displaced with relation to its cooperating work roll a given distance, depending on the thickness of the material being reduced, so that as material is fed into the mill, it contacts one of the rolls prior to the bite of .the rolls and is wrapped slightly over the roll surface giving an ironing effect to the material and thereby dampening it so that no fluttering or gutteringoccurs. As the thus dampened strip enters the bite of the roll, it is lying against the surface of the first roll contacted and presents a surface for reduction in the roll bite which is not free to flutter or gutter.

The means provided for horizontal displacement of the work rolls may be either manually or automatically adjustable. In the instance where automatically adjustable means are provided they are operably connected with a sensor means and a control means which cooperate to adjust the horizontal displacement when variations in the thickness of the reduced material occur. In operation, as the reduced material exits the roll bite, sensor means continually measure the material thickness across its width and a signal is impressed the control mans when any variation is noted. The control means in turn impresses a signal on the adjustable means which alters the horizontal displacement of the rolls to compensate for the thickness variation. Such control is automatic and continuous during the operation of the mill.

BRIEF DESCRIPTION OF THE DRAWING The above and other objects and features of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawing which forms a part of this specification and in which:

The single FIG. is an assembly drawing of the apparatus of the invention partly schematic with parts broken away to show detail and showing an exaggerated work roll ofiset.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing for a clearer understanding of the nature of the invention, the numeral 10 represents a partial section of a roll housing which serves as a mount for a pair of conventional backup rolls l2 and work rolls 14, the combination of the two sets of rolls and housing representing a four-high mill.

In a conventional four-high mill, the axes of the two sets of rolls are vertically aligned, the power driven backup rolls imparting a rotational speed to the work rolls proportional to the ratio of backup roll diameter to work roll diameter. It is obvious that as the material passes into and through the cooperating work rolls, being reduced in cross section thereby, the rolls act to exert considerable tension on the incoming material and such tension increases as the speed of the work rolls increases.

- With the increasing tension the incoming material flutters and gutters and such. fluttering and guttering. increases as the thickness of the material decreases. As a result of the fluttering and guttering of the material, it does not enter the bite of the rolls in the desired manner and pinching occurs causing the material to be unevenly rolled. It has now'been discovered that it is possible to horizontally displace one of the work rolls with respect to its cooperating roll so that the incoming material contactsone roll ahead of the roll bite and is thereby dampened to eliminate flutter and gutter and is ironed over the surface of the roll providing a flat surface for reduction in the roll-bite.

Turning again to the drawing, there is shown an apparatus to horizontally displace the top work roll a variable distance 28. with respect to the bottom work roll. The horizontal displacement means shownhere are hydraulic cylinders 18. Obviously, other adjustable .means could be substituted for the hydraulic cylinders since they represent merely one method of horizontally displacing one of the work rolls. Further, while the apparatus is shown for displacement of the upper work roll it could be as effectively associated with the lower work roll.

Still further, although automatically adjustable means are shown for displacement of the work roll, under certain conditions manual means such as offset plates or shims can be used to ofi'set the roll a fixed amount.

Turning again to the drawing, sensor means 20 are positioned on the exit side of the work rolls to continuously measure the thickness of the worked material across its width by measuring the horizontal displacement of the lower work roll and chock. The sensor means is operably connected to a control means 22 through line 24. The control means in turn is operably connected to the horizontal displacement means 18 through line 26. In the invention apparatus the sensor means 20 are transducers which are responsive to a change in thickness of the worked material and the control means is an electromagnetic actuator pressure-sensitive device. It is again obvious that other means may be substituted for the sensor and control means to accomplish the desired result of detecting a variation in thickness of the finished material and transmitting that information to adjust the horizontal displacement of the work roll to compensate for the variation.

In operation, the entering material 30 contacts one of the work rolls l4 and is dampened and ironed over an ironing area 32 of that roll prior to entering the roll bite. As the worked material exists the work rolls, a sensor means 20 continuously measures the thickness of the material across its width. When a variation in thickness is noted, the sensor means signals a control means 22 which in turn impresses a signal on the horizontal adjustment means 18 which horizontally displaces one of the work rolls a given amount to compensate for the thickness variation.

Although a preferred embodiment of this invention has been shown and-described, it is to be understood that various modifications and adaptations may be resorted to without departing from the scope of the appended claims.

lclaim:

the rolling surface of one of said rolls prior to entering said bite, thickness sensors disposed subsequent to the exit of said cooperating work rolls and hydraulic cylinder means responsive thereto to horizontally displace one of said work rolls whereby said angle of displacement of said work rolls relative to said pass line may be varied. 

